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MC146818 Dataheets PDF



Part Number MC146818
Manufacturers Motorola
Logo Motorola
Description REAL-TIME CLOCK PLUS RAM
Datasheet MC146818 DatasheetMC146818 Datasheet (PDF)

® MOTOROLA MC146818 Advance Information CMOS REAL-TIME CLOCK PLUS RAM (RTC) (HIGH-PERFORMANCE SILICON-GATE COMPLEMENTARY MOS) The MC146818 Real-Time Clock plus RAM is a peripheral device which includes the unique MOTEL concept for use with various microprocessors, microcomputers, and larger computers. This part REAL-TIME CLOCK PLUS RAM combines three unique features: a complete time-of-day clock with alarm and one hundred year calendar, a programmable periodic inter- rupt and square-wa.

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® MOTOROLA MC146818 Advance Information CMOS REAL-TIME CLOCK PLUS RAM (RTC) (HIGH-PERFORMANCE SILICON-GATE COMPLEMENTARY MOS) The MC146818 Real-Time Clock plus RAM is a peripheral device which includes the unique MOTEL concept for use with various microprocessors, microcomputers, and larger computers. This part REAL-TIME CLOCK PLUS RAM combines three unique features: a complete time-of-day clock with alarm and one hundred year calendar, a programmable periodic inter- rupt and square-wave generator, and 50 bytes of low-power static RAM. The MC146818 uses high-speed CMOS technology to interface I with 1 MHz processor buses, while consuming very little power. The Real-Time Clock plus RAM has two distinct uses. First, it is designed as a battery powered CMOS part (in an otherwise NMOSITTL system) including all the common battery backed-up functions such as L SUFFIX CERAMIC PACKAGE CASE 716 RAM, time, and calendar. Secondly, the MC146818 may be used with a CMOS microprocessor to relieve the software of the timekeeping workload and to extend the available RAM of an MPU such as the MC146805E2. P SUFFIX PLASTIC PACKAGE • Low-Power, High-Speed, High-Density CMOS CASE 709 • Internal Time Base and Oscillator • Counts Seconds, Minutes, and Hours of the Day • Counts Days of the Week, Date, Month, and Year • 3 V to 6 V Operation • Time Base Input Options: 4.194304 MHz, 1.048576 MHz, or 32.768 kHz S SUFFIX CERDIP PACKAGE CASE 623 • Time Base Oscillator for Parallel Resonant Crystals • 40 to 200 p.W Typical Operating Power at Low Frequency Time Base • 4.0 to 20 mW Typical Operating Power at High Frequency Time Base • Binary or BCD Representation of Time, Calendar, and Alarm Z SUFFIX CHIP CARRIER CASE 761 • 12- or 24-Hour Clock with AM and PM in 12-Hour Mode • Daylight Savings Time Option • Automatic End of Month Recognition • Automatic Leap Year Compensation PIN ASSIGNMENT • Microprocessor Bus Compatible • MOTEL Circuit for Bus Universality • Multiplexed Bus for Pin Efficiency • Interfaced with Software as 64 RAM Locations NC OSC1 OSC2 (3) 3 (4) (38) 23 (37) 22 VDD SOW PS • 14 Bytes of Clock and Control Registers ADO (8) (34) 21 CKOUT • 50 Bytes of General Purpose RAM • Status Bit Indicates Data Integrity • Bus Compatible Interrupt Signals (IRQ) • Three Interrupts are Separately Software Maskable and Testable AD1 AD2 AD3 (9) (10) (11) CKFS (32) 19 iFill (31)18 RESET Time-of-Day Alarm, Once-per-Second to Once-per-Day AD4 8 (12) (30) 17 DS Periodic Rates from 30.5 p.s to 500 ms End-of-Clock Update Cycle • Programmable Square-Wave Output Signal • Clock Output May Be Used as Microprocessor Clock Input At Time Base Frequency + 1 or +4 • 24-Pin Dual-In-Line Package AD5 (13) AD6 AD7 10 (18) 11 (19) VSS 12 (20) NC R/W AS a • Chip Carrier Also Available Pin numbers in parentheses represent equivalent Z suffix chip carrier pins. Pins that have not been designated for the chip carrier are not connected. This document contains information on a new product. Specifications and information herein are subject to change without notice. 3-996 MC146818 OSC1 OSC2 FIGURE 1 - BLOCK DIAGRAM CKOUT CKFS VDD -----. VSS ----+- Bus Interface Clock/ Calendar Update BCD/ Binary Increment Clock, Alarm, Calendar RAM 110 Bytes) User RAM 150 Bytes) SOW IRQ RESET PS I MAXIMUM RATINGS (Voltages referenced to VSSI Ratings Symbol Value Supply Voltage All Input Voltages Except OSC1 VDD Vin -0.3 to +8.0 VSS-05 to VDD+0.5 Current Drain per Pin Excluding VDD and VSS I 10 Operating Temperature Range MC146818 MC146818C (VDD = 3.0 to 5.5 V operation) TA TL to TH o to 70 -40 to 85 Storage Temperature Range Tstg - 55 to + 150 Unit V V mA °C °C THERMAL CHARACTERISTICS Characteristic Thermal Resistance Plastic Cerdip Ceramic Symbol Value Unit 120 ()JA 65 °C/W 50 This device contains circuitry to protect the inputs against damage due to high static voltages or electric fields; however, it is advised that normal precautions be taken to avoid application of any voltage higher than maximum rated voltages to this high-impedance circuit. For proper operation it is recommended that Vin and Vout be constrained to the range VSSslVin or Voutl s VDD. Reliability of operation is enhanced if unused inputs are tied to an appropriate logic voltage level le.g., either VSS or VDDI 3-997 MC146818 I DC ELECTRICAL CHARACTERISTICS (VDD=3 Vde VSS=O Vde TA=TL to TH unless otherwise noted I Characteristics Symbol Min Frequency of Operation Output Voltage fose VOL 32.768 - ILoad<10,..A VOH VDD-01 100 - Bus Idle CKOUT=fose, CL = 15 pF; SQW Disabled, CE=VDD-0.2; CL (OSC21= 10 pF fose= 32.768 kHz 100 - Quiescent fose= DC; OSC1 = DC; All Other Inputs=VDD-0.2 V; No Cloek 1003 1004 - Output High Voltage ILLoad= -0.25 mA. All Outputsl VOH 2.7 Output Low Voltage (ILoad=025 mA, All Outputsl Input High Voltage ADO-AD7, OS, AS, R/W, CE, RESET, CKF.


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